WASHINGTON — A new European study concludes a few years of cellphone use didn't raise children's risk of brain cancer.
Repeated studies in adults have been reassuring, too, although an arm of the World Health Organization said this spring that there is a possibility cellphones pose a risk.
Wednesday's report marks a first step in examining the question in children, whose brains still are developing.
Swiss scientists tracked 352 children ages 7 to 19 who were diagnosed with brain cancer between 2004 and 2008 in Norway, Denmark, Sweden and Switzerland. They interviewed the kids about their prior cellphone use, and compared them with 646 healthy children and teens.
About half of both groups said they were regular cellphone users, researchers reported in the Journal of the National Cancer Institute. Children who said they started to use cellphones at least five years earlier weren't at higher risk of cancer than those who said they'd never regularly used them. Duration or number of calls, or which side of the head the phone was held, also didn't make a statistically significant difference.
However, the researchers could check phone-company records for a subset of the kids. The few dozen who'd had cellphone service the longest, about three years or more, did have an increased risk.
The researchers at the Swiss Tropical and Public Health Institute noted that childhood brain cancer hasn't increased since cellphones appeared.
But they encouraged more research, saying their study wasn't large enough to rule out a small risk and that kids' cellphone use has increased since 2008.
Another question is longer-term use, although many children text more than talk.
"This is a very important study," said Elizabeth Ward of the American Cancer Society, but one that will be debated. "It is important that additional studies be done in children, adolescents and young adults with early life exposure to mobile phones."
The cancer society says people who are concerned about a possible risk can keep the phone away from their heads and limit children's use.